The incorporation of electronic devices with pneumatic tire structures yields many practical advantages. Tire electronics may include sensors and other components for obtaining information regarding various physical parameters of a tire, such as temperature, pressure, number of tire revolutions, vehicle speed, etc. Such performance information may become useful in tire monitoring and warning systems, and may even potentially be employed with feedback systems to regulate proper tire pressure levels and with vehicle performance and control systems.
Yet another potential capability offered by electronics systems integrated with tire structures corresponds to asset tracking and performance characterization for commercial vehicular applications. Commercial truck fleets, aviation crafts and earthmover/mining vehicles are all viable industries that could utilize the benefits of tire electronic systems and related information transmission. Tire sensors can determine the distance each tire in a vehicle has traveled and thus aid in maintenance planning for such commercial systems. Vehicle location and performance can be optimized for more expensive applications such as those concerning earth mining equipment. Entire fleets of vehicles could be tracked using RF tag transmission.
Certain piezoelectric materials have been utilized in various applications related to tire and wheel assemblies and other vibrational systems. For example, piezoelectric transducers can be used as sensors to measure the response to an impressed acoustic field. Piezoelectric actuators can convert an applied electric field into kinematic energy and mechanical displacement. Piezoelectric reeds and other specialized piezoelectric formations have been employed to convert mechanical vibrations from tire rotation to electrical energy for powering tire electronics assemblies.
Utilization of piezoelectric materials in the above applications and others is often limited due to the unique nature and the potential limitations inherently associated with the structure and performance abilities of piezoelectric materials. Piezoelectric crystals and fibers are often subject to cracking and/or breaking under high strain levels. Piezoelectric ceramics require at least one poling treatment to align the polar domains of a material thus rendering it able to function as a sensor or actuator device. The integration of electrodes with a piezoelectric material must typically be precisely configured and maintained for effective operation of a piezoelectric device. Furthermore, certain types of piezoelectric materials may not be well suited for a given application or in a given environment. For example, although lead zirconate titanate (PZT) material are often characterized by sexiirable performance characteristics, lead-based materials may not be preferred for certain applications.
In accordance with the present subject matter, it is appreciated that certain advantages of piezoelectric materials have long been recognized. However, such technology is constantly improving, thus potentially affording applications that utilize piezoelectric materials and piezoelectric structures with improved operating capabilities. The present invention addresses the presently disclosed concerns and others as related to the use of piezoelectric materials for various tire and wheel assembly applications and offers improved piezoelectric structures for such applications and others.